Improvement in machines for turning shafting



2 Sheets--Sheet1.

JOHN FENSON.

Improvement in Machines for Turning Shafting. N0 126 538, Patented May7,1872.

AM. FHOm 'L/TH06HAFHIC 60. N K (OSBOHNE PROCESS) 2 Sheets--Sheet 2.

y JOH'N FENSON. Improvement in Machines for Turning Shafting.

No, 126,538, Patented May 7,1872.

PATENT OFFICE.

JOHN FENSOM, OF TORONTO, CANADA.

IMPROVEMENT IN MACHINES FOR TURNING SHAFTING.

Specification forming part of Letters Patent No. 126,538, dated May 7,1872.

SPECIFICATION.

I, J OHN FENsoM, of the city of Toronto, in the county of York, Provinceof Ontario and Dominion of Canada, engineer, have invented certain newand useful Improvements in Tools for Turning Shafting, &c., of which thefollowing is a specification:

1V crime and Objects of the Invention.

The first part of my invention relates to an improved cutter or die forturning shafting, &c. and consists in forming the front cuttingedge ofthe same like a chaser, the thread of which gradually decreases in depthuntil it runs completely out, leaving the back portion a broadcutting-edge, which is in the same plane as the top of the first thread.By this means the thread which is commenced by the front cutting-edge isutilized as a feeder for the cutter, and the thread so formed isgradually cut away as the threads in the cutter become less deep, andthe threads are complete- 1y removed by the back cutting-edge. Theeffect of cutters thus formed is to distribute the cutting-points, andthereby reduce the friction upon them, while at the same time the cutteris self-feedin g. The second part of my invention relates to atrough-shaped lathe-bed, constructed without the ordinary heads, thespindles fitting through each end of the lathebed in such a manner thatthe centers are below the water-line when the trough-shaped bed isfilled with water, the object of this part of the invention being tokeep the metal under operation thoroughly lubricated and perfectly coolwhile being turned; but that the nature of my invention may be fullyunderstood I will proceed to describe the same more in detail by aid ofthe accompanying drawing.

Description of the Drawing.

Figure 1, Sheet 1, represents an elevation and plan of cutters A, fullsize, arranged according to my invention. Fig. 2 represents an end viewof a lathe-bed, B; Fig. 3, a sectional end view of the same takenthrough the line X Y. Fig. 4 is a sectional end view taken through theline Z W; and Fig. 5 is aside elevation, with part of the side of theapparatus broken away, and showing the tool-rest D and the steady rest Fin section. Fig. 1, Sheet 2, represents a sectional end view of anordinary blacksmiths stock, full size, in which the cutters A arerepresented in the act of turning a piece of shaftin g.

It will be seen that the front a of the cutters A commences with a fullthread, which gradually decreases in depth until it runs completely outand leaves the back portion b a broad cutting-edge, which entirelyremoves the thread cut or formed by the front a. By this meansblacksmiths and others who do not usually possess machinery for turningare enabled with my dies or cutters A to employ their ordinary stock forthat purpose.

It is unnecessary for me to enumerate the various ways in which myimproved dies or cutters A may be applied, either singly or in anynumber. They may be applied to common or bolt-cutting lathes with orwithout the ordinary feeding-gear, as required; and, in in fact, theprinciple of my cutters can be adapted to any description of turning.

I will now describe the second part of my invention, which consists of atrough-shaped lathe-bed, constructed in such manner that the spindlerevolves within the bed and below the line of the water which the sameis intended to contain when the machine is in operation.

By reference to the drawing on Sheet 1 it will be seen that the spindlepasses through the end of the bed B, which is fitted with suitablejournal-boxes, 810., and the tool-rest D is so shaped that the metalbeing turned may be operated upon. The position of the shaft E is shownby the drawing.

Having thus described my invention, and means by which the same may becarried into effect, I would have it understood that I do not confinemyself to the precise an gle shonn in the drawing, at which the frontcutting edge a of the cutter A decreases in depth as the same may bevaried without departing from the peculiar character of my invention;nor do I claim any peculiar design for the bed B or tool-rest D, so longas the main features shown and described are adhered to; nor do Iconfine myself to any kind of turning-tool for the rest D; but

What I do claim is- 1. A cutter or die, A, with a thread cut in thefront portion a thereof, which gradually decreases in depth until itcompletely runs out, leaving the back portion 11 broad and in the sameplane as the top of the first thread, subthe steady rest F,substantially as and for the stantially as and for the purposespecified. purpose specified.

2. I claim the combination with the trough- City of Toronto, 24th day ofOctober, 1871. like lathe-bed B and the head and tail spin- JOHN FENSOM.dies which pass through the ends thereof be- \Vitnesses: low the levelto which the said bed may be DONALD C. RIDOUT,

filled with water, the sliding tool-rest D, and CLAUD. L. CAYLEY.

